"Kate Callahan apparently was on hand for their bar-closing karaoke night last season," wrote Michael Ausiello. "Nonetheless, they’re a bit startled by the way she resurfaces in their world."

Showrunner Erica Messer elaborated, saying, "You see [Kate] doing something you don’t see our team ever doing, which is schmoozing with a bad guy, working undercover to take a pedophile down. We’ve never seen our team pretend to like a criminal, so right off the bat she’s different in that way."

Hewitt was announced as a series regular at the beginning of July. At the time, Messer said, “Many of us on the show have enjoyed working with her over the years and look forward to again. We have exciting storylines planned for her character and the entire BAU team as we head into our 10th season."

A.J. Cook, meanwhile, has given some less detailed info about the upcoming season.

"I know we're all thinking something might happen [in Season 10], but we don't know yet," she told RTé. "So I don't know, we'll see. It's such a milestone, so you know it's going to be big, and I completely put my trust in our writers and our showrunner... I'm sure it'll be a rollercoaster ride of excitement."